The invention is directed to novel macrolide derivatives, pharmaceutical compositions comprising them, and methods of using them in the treatment or prevention of, for example, bacterial or protozoa infections in mammals, fish, or birds.
Macrolide antibiotics that can be used in the treatment or prevention of bacterial or protozoa infections in mammals, fish, or birds include various derivatives of erythromycin A, such as azithromycin, which is commercially available and is referred to in U.S. Pat. Nos. 4,474,768 and 4,517,359, both of which are incorporated herein by reference. Examples of additional macrolides are disclosed in: U.S. patent application Ser. No. 09/424,104, filed May 29, 1998 (Brian S. Bronk, Michael A. Letavic, Takushi Kaneko, Bingwei V. Yang, E. A. Glazer, and Hengmiao Cheng); WO 98/01571 (Peter Francis Leadlay, James Staunton, Jesus Cortes and Michael Stephen Pacey); WO 98/01546 (Peter Francis Leadlay, James Staunton, and Jesus Cortes); U.S. patent application Ser. No. 09/554,988, filed Dec. 21, 1998 (John P. Dirlam); U.S. Pat. No. 6,043,227, issued Mar. 28, 2000; and WO 98/09978, all of which are incorporated herein by reference.
This invention is directed to novel compounds of Formula 1: 
and to pharmaceutically acceptable salts, solvates, and prodrugs thereof, wherein:
X is xe2x80x94CH2NR7xe2x80x94 or xe2x80x94NR7CHR6xe2x80x94, wherein the first dash of each of the foregoing X groups is attached to Y and the last dash of each of the foregoing X groups is attached to the C-8 carbon;
Y is xe2x80x94CH(CH3)xe2x80x94;
or X, Y, and R3 can be taken together to form the moiety of Formula a 
Z is selected from the group consisting of xe2x80x94C(O)xe2x80x94, xe2x80x94CH(xe2x80x94OR8)xe2x80x94, and the moiety of Formula b 
R1 is H or a hydroxy protecting group;
R2 is xe2x80x94OR13, or R2 and R3 are taken together to form the moiety of Formula c 
or if X is xe2x80x94NR7CHR6xe2x80x94, R2 and R6 can be taken together to form the moiety of Formula d 
R3 is xe2x80x94OC(O)R14, or R3, X, and Y are taken together to form the moiety of Formula a, or R3 and R2are taken together to form the moiety of Formula c;
R4 is xe2x80x94OR15;
R5 is an alpha-branched C2-C8 alkyl, C2-C8 alkenyl, C2-C8 alkynyl, C2-C8 alkoxyalkyl, or C2-C8 alkylthioalkyl group optionally substituted with at least one hydroxyl group; an alpha-branched C2-C5 alkyl group attached to a C5-C8 cycloalkyl group; a C3-C8 cycloalkyl or cycloalkenyl group optionally substituted with at least one moiety selected from the group consisting of methyl, hydroxyl, halo, and C1-C4 alkyl groups; or a 3-6 membered saturated, or fully or partially unsaturated, heterocycle comprising at least one atom of oxygen or sulphur and optionally substituted with one or more C1-C4 alkyl groups or halogen atoms;
R6 is H, or if X is xe2x80x94NR7CHR6xe2x80x94, R6 and R2 can be taken together to form the moiety of Formula d;
R7 is selected from the group consisting of H, C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, xe2x80x94(CH2)m(C6-C10 aryl), and xe2x80x94(CH2)m(5-10 membered heteroaryl), wherein the alkyl, alkenyl, aryl, heteroaryl, and alkynyl moieties of the foregoing R7 groups are optionally substituted with 1 to 3 substituents independently selected from the group consisting of halo, cyano, nitro, trifluoromethyl, azido, xe2x80x94C(O)R11, xe2x80x94OC(O)R11, xe2x80x94NR11C(O)R12, xe2x80x94C(O)NR11R12, xe2x80x94NR11R12, hydroxy, C1-C6 alkyl, C1-C6 alkoxy, C6-C10 aryl, and 5-10 membered heteroaryl;
R8 is selected from the group consisting of H, C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, xe2x80x94C(O)R17, xe2x80x94C(O)NR17R18, (CH2)m(C6-C10 aryl), and xe2x80x94(CH2)m(5-10 membered heteroaryl), wherein the alkyl, alkenyl, alkynyl, aryl, and heteroaryl moieties of the foregoing R8 groups are optionally substituted with 1 to 3 substituents independently selected from the group consisting of halo, cyano, nitro, trifluoromethyl, azido, xe2x80x94C(O)R11, OC(O)R11, xe2x80x94NR11C(O)R12, xe2x80x94C(O)NR11R12, xe2x80x94NR11R12, hydroxy, C1-C6 alkyl, C1-C6 alkoxy, C6-C10 aryl, and 5-10 membered heteroaryl;
R9 is hydroxy;
R10 is selected from the group consisting of H, C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, cyano, xe2x80x94CH2S(O)nR11, xe2x80x94CH2OR11, xe2x80x94CH2NR11R12, xe2x80x94(CH2)m(C6-C8 aryl membered heteroaryl), wherein the alkyl, alkenyl, alkynyl, aryl, and heteroaryl moieties of the foregoing R10 groups are optionally substituted with 1 to 3 substituents independently selected from the group consisting of halo, cyano, nitro, trifluoromethyl, azido, xe2x80x94C(O)R11, xe2x80x94OC(O)R11, xe2x80x94NR11C(O)R12, xe2x80x94C(O)NR11R12, xe2x80x94NR11R12, hydroxy, C1-C6 alkyl, C1-C6 alkoxy, C6-C10 aryl, and 5-10 membered heteroaryl;
each R11 and R12 is independently selected from the group consisting of H, C1-C6 alkyl, C2-C6 alkenyl, (CH2)m(C6-C1aryl), (CH2)m(5-10 membered heteroaryl), and C2-C10 alkynyl, wherein the alkyl, alkenyl, aryl, heteroaryl, and alkynyl moieties of the foregoing R11 and R12 groups are optionally substituted with 1 to 3 substituents independently selected from the group consisting of halo, cyano, nitro, trifluoromethyl, C1-C6 alkyl, and C1-C6 alkoxy;
R13 is selected from the group consisting of H, C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, xe2x80x94R16(C6-C10 aryl), and xe2x80x94R16(5-10 membered heteroaryl), wherein the alkyl, alkenyl, alkynyl, aryl, and heteroaryl moieties of the foregoing R13 groups are optionally substituted with 1 to 3 substituents independently selected from the group consisting of halo, cyano, nitro, trifluoromethyl, azido, xe2x80x94C(O)R11, xe2x80x94OC(O)R11, xe2x80x94NR11C(O)R12, xe2x80x94C(O)NR11R12, xe2x80x94NR11R12, hydroxy, C1-C6 alkyl, C1-C6 alkoxy, C6-C10 aryl, and 5-10 membered heteroaryl;
R14 is selected from the group consisting of C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, xe2x80x94(CH2)m(C6-C10 aryl), and xe2x80x94(CH2)m(5-10 membered heteroaryl), wherein the alkyl, alkenyl, aryl, heteroaryl, and alkynyl moieties of the foregoing R14 groups are optionally substituted with 1 to 3 substituents independently selected from the group consisting of halo, cyano, nitro, trifluoromethyl, azido, xe2x80x94C(O)R11, xe2x80x94OC(O)R11, xe2x80x94NR11C(O)R12, xe2x80x94C(O)NR11R12, xe2x80x94NR11R12, hydroxy, C1-C6 alkyl, C1C6 alkoxy, C6-C10 aryl, and 5-10 membered heteroaryl;
each R15 is independently selected from the group consisting of H, C1-C10alkyl, C2-C10-alkenyl, C2-C10 alkynyl, xe2x80x94(CH2)m(C6-C10 aryl), and xe2x80x94(CH2)m(5-10 membered heteroaryl), wherein the alkyl, alkenyl, alkynyl, aryl, and heteroaryl moieties of the foregoing R15 groups are optionally substituted with 1 to 3 substituents independently selected from the group consisting of halo, cyano, nitro, trifluoromethyl, azido, xe2x80x94C(O)R11, xe2x80x94OC(O)R11, xe2x80x94NR11C(O)R12, xe2x80x94C(O)NR11R12, xe2x80x94NR11R12, hydroxy, C1-C6 alkyl, C1-C6 alkoxy, C6-C10 aryl, and 5-10 membered heteroaryl;
R16 is selected from the group consisting of C1-C6 alkyl, C3-C6 alkenyl, and C3-C6 alkynyl, wherein the alkyl, alkenyl, and alkynyl moieties of the foregoing R16 groups are optionally substituted with 1 to 3 substituents independently selected from the group consisting of halo, cyano, nitro, trifluoromethyl, azido, xe2x80x94C(O)R11, xe2x80x94OC(O)R11, xe2x80x94NR11C(O)R12, xe2x80x94C(O)NR11R12, xe2x80x94NR11R12, hydroxy, C1-C6 alkyl, C1C6 alkoxy, C6-C10 aryl, and 5-10 membered heteroaryl, and wherein at least one carbon atom of each of the foregoing R16 groups can optionally be replaced with 1 to 3 atoms or moieties independently selected from group consisting of O, N(R15), and S;
each of R17 and R18 is independently selected from the group consisting of H, C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, xe2x80x94(CH2)m(C6-C10 aryl), and xe2x80x94(CH2)m(5-10 membered heteroaryl), wherein the alkyl, alkenyl, alkynyl, aryl, and heteroaryl moieties of the foregoing R17 and R18 groups are optionally substituted with 1 to 3 substituents independently selected from the group consisting of halo, cyano, nitro, trifluoromethyl, azido, xe2x80x94C(O)R11, xe2x80x94OC(O)R11, xe2x80x94NR11C(O)R12, xe2x80x94C(O)NR11R12, xe2x80x94NR11R12, hydroxy, C1-C6 alkyl, C1-C6 alkoxy, C6-C10 aryl, and 5-10 membered heteroaryl;
each n independently represents an integer of from 0 to 2; and
each m independently represents an integer of from 0 to 4.
In a preferred compound of Formula 1, X is xe2x80x94CH2NR7xe2x80x94 or xe2x80x94NR7CHR6xe2x80x94, Z is a moiety of Formula b, R2 is OH, R3 is xe2x80x94OC(O)R14, R4 is OH, and R6 is H.
In another preferred compound of Formula 1, X is xe2x80x94NR7CHR6xe2x80x94, Z is a moiety of Formula b, R2 and R6 are taken together to form a moiety of Formula d, R3 is xe2x80x94OC(O)R14, R4 is OH, and R7 is CH3.
In another preferred compound of Formula 1, X, Y, and R3 are taken together to form a moiety of Formula a, Z is a moiety of Formula b, R2 is OH, and R4 is OH.
In another preferred compound of Formula 1, X is xe2x80x94CH2NR7xe2x80x94 or xe2x80x94NR7CHR6xe2x80x94, Z is a moiety of Formula b, R2 and R3 are taken together to form a moiety of Formula c, and R4 is OH.
In another preferred compound of Formula 1, X, Y, and R3 are taken together to form a moiety of Formula a, Z is xe2x80x94CH(OR8)xe2x80x94, R2 is xe2x80x94OR13, and R4 is OR15.
In another preferred compound of Formula 1, X, Y, and R3 are taken together to form a moiety of Formula a, Z is xe2x80x94C(O)xe2x80x94, R2 is xe2x80x94OR13, and R4 is OR15. In a more preferred compound of Formula 1, R1 is H; R5 is ethyl; R15 is H or methyl, and R13 is a moiety of Formula e-g 
wherein R19 is C6-C10 aryl or 5-10 membered heteroaryl, wherein the aryl and heteroaryl moieties of the foregoing R19 groups are optionally substituted with 1 to 3 substituents selected from the group consisting of halo, cyano, nitro, trifluoromethyl, azido, xe2x80x94C(O)R11, xe2x80x94OC(O)R12, xe2x80x94NR11C(O)R12, xe2x80x94C(O)NR11R12, xe2x80x94NR11R12, hydroxy, C1-C6 alkyl, C1-C6 alkoxy, C6-C10 aryl, and 5-10 membered heteroaryl. In an even more preferred compound of Formula 1, R19 is selected from the group consisting of phenyl, 2-quinolyl, 3-quinolyl, 4-quinolyl, 5-quinolyl, 6-quinolyl, 7-quinolyl, 8-quinolyl, 2-pyridyl, 3-pyridyl, and 4-pyridyl.
In another preferred compound of Formula 1, R5 is selected from the group consisting of ethyl, isopropyl, cyclopropyl, sec-butyl, cyclobutyl, cyclopentyl, methylthioethyl, and furyl.
The invention further encompasses a method of preparing a compound of Formula 2
wherein R2, R5, R9, R10, and R15 are defined herein, which comprises contacting a compound of Formula f 
with a Grignard reagent for a time and at a temperature sufficient to form a compound of Formula 2.
The invention further encompasses a method of preparing a compound of Formula 4
wherein R5, R9, R10, and R15 are defined herein, which comprises contacting a compound of Formula h 
with an amine oxidizing reagent for a time and at a temperature sufficient to form a compound of Formula 4. In a preferred embodiment of the invention, the amine oxidizing reagent is selected from the group consisting of N-bromosuccinimide, N-chlorosuccinimide, iodine, and bromine.
The invention further encompasses a method of preparing a compound of Formula 5
wherein R2, R5, R9, and R10 are defined herein, which comprises contacting a compound of Formula i 
with a Grignard reagent or a base for a time and at a temperature sufficient to form a compound of Formula 5. In a preferred method, the Grignard reagent is benzyl magnesium chloride. In another preferred method, the base is isopropylcyclohexylamino magnesium chloride.
The invention further encompasses a method of forming a compound of Formula 7
wherein R2 and R5 are defined herein, which comprises contacting a compound of Formula 5
wherein R9 and R10 are defined herein, with acidic conditions for a time and at a temperature sufficient to form a compound of Formula 7.
The invention further encompasses pharmaceutical compositions comprising a compound of Formula 1 or a pharmaceutically acceptable salt, solvate, or prodrug thereof and a pharmaceutically acceptable carrier.
The invention further encompasses a method of treating a bacterial or protozoal infection in a mammal, fish, or bird which comprises administering to a mammal, fish or bird in need of such treatment a therapeutically effective amount of a compound of Formula 1 or a pharmaceutically acceptable salt, solvate, or prodrug thereof.
As used herein and unless otherwise indicated, the term xe2x80x9cinfection(s)xe2x80x9d includes bacterial infection(s) and protozoa infection(s) that occur in mammals, fish or birds as well as disorders related to bacterial infections and protozoa infections that may be treated or prevented by administering antibiotics such as the compounds of the invention. Such bacterial infections and protozoa infections and disorders related to such infections include the following: pneumonia, otitis media, sinusitus, bronchitis, tonsillitis, and mastoiditis related to infection by Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, Staphylococcus aureus, or Peptostreptococcus spp.; pharynigitis, rheumatic fever, and glomerulonephritis related to infection by Streptococcus pyogenes, Groups C and G streptococci, Clostridium diptheriae, or Actinobacillus haemolyticum; respiratory tract infections related to infection by Mycoplasma pneumoniae, Legionella pneumophila, Streptococcus pneumoniae, Haemophilus influenzae, or Chlamydia pneumoniae; uncomplicated skin and soft tissue infections, abscesses and osteomyelitis, and puerperal fever related to infection by Staphylococcus aureus, coagulase-positive staphylococci (e.g., S. epidermidis and S. hemolyticus), Streptococcus pyogenes, Streptococcus agalactiae, Streptococcal groups C-F (minute-colony streptococci), viridans streptococci, Corynebacterium minutissimum, Clostridium spp., or Bartonella henselae; uncomplicated acute urinary tract infections related to infection by Staphylococcus saprophyticus or Enterococcus spp.; urethritis and cervicitis; and sexually transmitted diseases related to infection by Chlamydia trachomatis, Haemophilus ducreyi, Treponema pallidum, Ureaplasma urealyticum, or Neiserria gonorrheae; toxin diseases related to infection by S. aureus (food poisoning and Toxic shock syndrome), or Groups A, B, and C streptococci; ulcers related to infection by Helicobacter pylori; systemic febrile syndromes related to infection by Borrelia recurrentis; Lyme disease related to infection by Borrelia burgdorferi; conjunctivitis, keratitis, and dacrocystitis related to infection by Chlamydia trachomatis, Neisseria gonorrhoeae, S. aureus, S. pneumoniae, S. pyogenes, H. influenzae, or Listeria spp.; disseminated Mycobacterium avium complex (MAC) disease related to infection by Mycobacterium avium, or Mycobacterium intracellulare; gastroenteritis related to infection by Campylobacter jejuni; intestinal protozoa related to infection by Cryptosporidium spp.; odontogenic infection related to infection by viridans streptococci; persistent cough related to infection by Bordetella pertussis; gas gangrene related to infection by Clostridium perfringens or Bacteroides spp.; and atherosclerosis related to infection by Helicobacter pylori or Chlamydia pneumoniae. Bacterial infections and protozoa infections and disorders related to such infections that may be treated or prevented in animals include the following: bovine respiratory disease related to infection by P. haem., P. multocida, Mycoplasma bovis, or Bordetella spp.; cow enteric disease related to infection by E. coli or protozoa (e.g., coccidia and cryptosporidia); dairy cow mastitis related to infection by Staph. aureus, Strep. uberis, Strep. agalactiae, Strep. dysgalactiae, Klebsiella spp., Corynebacterium, or Enterococcus spp.; swine respiratory disease related to infection by A. pleuro., P. multocida, or Mycoplasma spp.; swine enteric disease related to infection by E. coli, Lawsonia intracellularis, Salmonella, or Serpulina hyodyisinteriae; cow footrot related to infection by Fusobacterium spp.; cow metritis related to infection by E. coli; cow hairy warts related to infection by Fusobacterium necrophorum or Bacteroides nodosus; cow pink-eye related to infection by Moraxella bovis; cow premature abortion related to infection by protozoa (e.g., neosporium); urinary tract infection in dogs and cats related to infection by E. coli; skin and soft tissue infections in dogs and cats related to infection by Staph. epidermidis, Staph. intermedius, coagulase neg. Staph. or P. multocida; and dental or mouth infections in dogs and cats related to infection by Alcaligenes spp., Bacteroides spp., Clostridium spp., Enterobacter spp., Eubacterium, Peptostreptococcus, Porphyromonas, or Prevotella. Other bacterial infections and protozoa infections and disorders related to such infections that may be treated or prevented in accord with the method of the present invention are referred to in J. P. Sanford et al., xe2x80x9cThe Sanford Guide To Antimicrobial Therapy,xe2x80x9d 26th Edition, (Antimicrobial Therapy, Inc., 1996).
As used herein and unless otherwise indicated, the term xe2x80x9ctreatmentxe2x80x9d includes treatment or prevention.
As used herein and unless otherwise indicated, the term xe2x80x9chaloxe2x80x9d means fluoro, chloro, bromo or iodo. Preferred halo groups are fluoro, chloro and bromo.
As used herein and unless otherwise indicated, the term xe2x80x9calkylxe2x80x9d includes saturated monovalent hydrocarbon radicals having straight, cyclic or branched moieties, or a combination of the foregoing moieties. An alkyl group can include one or two double or triple bonds. It is understood that cyclic alkyl groups comprise at least three carbon atoms.
As used herein and unless otherwise indicated, the term xe2x80x9calkanoylxe2x80x9d includes xe2x80x94C(O)-alkyl groups wherein xe2x80x9calkylxe2x80x9d is defined herein.
As used herein and unless otherwise indicated, the term xe2x80x9caralkylxe2x80x9d includes an aryl substituted with an alkyl group or an alkyl substituted with an aryl group.
As used herein and unless otherwise indicated, the term xe2x80x9carylxe2x80x9d includes an organic radical derived from an aromatic hydrocarbon by removal of one hydrogen, such as phenyl or naphthyl.
As used herein and unless otherwise indicated, xe2x80x9cAcxe2x80x9d indicates an acetyl group.
As used herein and unless otherwise indicated, xe2x80x9cMexe2x80x9d indicates a methyl group.
As used herein and unless otherwise indicated, xe2x80x9cEtxe2x80x9d indicates an ethyl group.
As used herein and unless otherwise indicated, the term xe2x80x9cheteroarylxe2x80x9d means an aryl group wherein at least one carbon atom has been replaced with an atom selected from the group consisting of O, S, and N.
As used herein and unless otherwise indicated, the terms xe2x80x9cheterocyclic groupxe2x80x9d and xe2x80x9cheterocyclexe2x80x9d include aromatic and non-aromatic heterocyclic groups containing one or more heteroatoms each selected from O, S and N. Non-aromatic heterocyclic groups include groups having only 3 atoms in their ring system, but aromatic heterocyclic groups (i.e., heteroaryl groups) must have at least 5 atoms in their ring system. Heterocyclic groups include benzo-fused ring systems and ring systems substituted with one or more oxo moieties. An example of a 4 membered heterocyclic group is azetidinyl (derived from azetidine). An example of a 5 membered heterocyclic group is thiazolyl, and an example of a 10 membered heterocyclic group is quinolinyl. Examples of non-aromatic heterocyclic groups are pyrrolidinyl, tetrahydrofuranyl, tetrahydrothienyl, tetrahydropyranyl, tetrahydrothiopyranyl, piperidino, morpholino, thiomorpholino, thioxanyl, piperazinyl, azetidinyl, oxetanyl, thietanyl, homopiperidinyl, oxepanyl, thiepanyl, oxazepinyl, diazepinyl, thiazepinyl, 1,2,3,6-tetrahydropyridinyl, 2-pyrrolinyl, 3-pyrrolinyl, indolinyl, 2H-pyranyl, 4H-pyranyl, dioxanyl, 1,3-dioxolanyl, pyrazolinyl, dithianyl, dithiolanyl, dihydropyranyl, dihydrothienyl, dihydrofuranyl, pyrazolidinyl, imidazolinyl, imidazolidinyl, 3-azabicyclo[3.1.0]hexanyl, 3-azabicyclo[4.1.0]heptanyl, 3H-indolyl, and quinolizinyl. Examples of aromatic heterocyclic groups are pyridinyl, imidazolyl, pyrimidinyl, pyrazolyl, triazolyl, pyrazinyl, tetrazolyl, furyl, thienyl, isoxazolyl, thiazolyl, oxazolyl, isothiazolyl, pyrrolyl, quinolinyl, isoquinolinyl, indolyl, benzimidazolyl, benzofuranyl, cinnolinyl, indazolyl, indolizinyl, phthalazinyl, pyridazinyl, triazinyl, isoindolyl, pteridinyl, purinyl, oxadiazolyl, thiadiazolyl, furazanyl, benzofurazanyl, benzothiophenyl, benzothiazolyl, benzoxazolyl, quinazolinyl, quinoxalinyl, naphthyridinyl, and furopyridinyl. The foregoing groups, as derived from the compounds listed above, may be C-attached or N-attached where such attachment is possible. For instance, a group derived from pyrrole can be pyrrol-1-yl (N-attached) or pyrrol-3-yl (C-attached).
As used herein and unless otherwise indicated, the phrase xe2x80x9cpharmaceutically acceptable salt(s)xe2x80x9d includes salts of acidic or basic groups which may be present in the compounds of the present invention. The compounds of the present invention that are basic in nature are capable of forming a wide variety of salts with various inorganic and organic acids. The acids that can be used to prepare pharmaceutically acceptable acid addition salts of such basic compounds are those that form non-toxic acid addition salts, i.e., salts containing pharmacologically acceptable anions, such as, but not limited to, the hydrochloride, hydrobromide, hydroiodide, nitrate, sulfate, bisulfate, phosphate, acid phosphate, isonicotinate, acetate, lactate, salicylate, citrate, acid citrate, tartrate, pantothenate, bitartrate, ascorbate, succinate, maleate, gentisinate, fumarate, gluconate, glucuronate, saccharate, formate, benzoate, glutamate, methanesulfonate, ethanesulfonate, benzenesulfonate, p-toluenesulfonate, and pamoate [i.e., 1,1xe2x80x2-methylene-bis-(2-hydroxy-3-naphthoate)] salts. Compounds of the invention that include a basic moiety, such as an amino group, can form pharmaceutically acceptable salts with various amino acids in addition to the acids mentioned above.
Those compounds of the present invention that are acidic in nature are capable of forming base salts with various pharmacologically acceptable cations. Examples of such salts include the alkali metal or alkaline earth metal salts, and calcium, magnesium, sodium and potassium salts in particular.
In the chemical structures depicted herein, a wavy line indicates that the stereochemistry at the chiral center to which the wavy line is connected is either an R or S configuration where the wavy line is connected to a carbon atom.
The compounds of the present invention have asymmetric centers and therefore exist in different enantiomeric and diastereomeric forms. This invention relates to the use of all optical isomers and stereoisomers of the compounds of the present invention, and mixtures thereof, and to all pharmaceutical compositions and methods of treatment that may employ or contain them. Compounds of Formula 1 can also exist as tautomers. This invention relates to the use of all such tautomers and mixtures thereof.
This invention further encompasses isotopically-labeled compounds of Formula 1 which are identical to those of Formula 1 but for the fact that one or more atoms are replaced by an atom having an atomic mass or mass number different from the atomic mass or mass number usually found in nature. Examples of isotopes that can be incorporated into compounds of the invention include isotopes of hydrogen, carbon, nitrogen, oxygen, phosphorous, fluorine and chlorine, such as 2H, 3H, 13C, 14C, N, 18O, 17O, 35S, 18F, and 36Cl, respectively. Isotopically labeled compounds of Formula 1, and pharmaceutically acceptable salts, solvates, and prodrugs thereof are encompassed by this invention. Certain isotopically-labeled compounds of the present invention, for example those into which radioactive isotopes such as 3H and 14C are incorporated, are useful in drug and/or substrate tissue distribution assays. Tritiated (i.e., 3H) and carbon-14 (i.e., 14C) isotopes are particularly preferred for their ease of preparation and detectability. Further, substitution with heavier isotopes such as deuterium (i.e., 2H) can afford certain therapeutic advantages resulting from greater metabolic stability, for example increased in vivo half-life or reduced dosage requirements and, hence, may be preferred in some circumstances. Isotopically labeled compounds of the invention and prodrugs thereof can generally be prepared by carrying out the procedures disclosed herein by substituting a readily available isotopically labeled reagent for a non-isotopically labeled reagent.
This invention also encompasses pharmaceutical compositions containing prodrugs of compounds of Formula 1 and methods of treating bacterial or protozoal infections which comprise the administration of prodrugs of compounds of Formula 1. Compounds of the invention having free amino, amido, hydroxy, or carboxylic groups can be converted into prodrugs. Prodrugs include compounds wherein an amino acid residue, or a polypeptide chain of two or more (e.g., two, three or four) amino acid residues is covalently joined through an amide or ester bond to a free amino, hydroxy or carboxylic acid group of compounds of Formula 1. The amino acid residues include, but are not limited to, the 20 naturally occurring amino acids commonly designated by three letter symbols and also includes 4-hydroxyproline, hydroxylysine, demosine, isodemosine, 3-methylhistidine, norvalin, beta-alanine, gamma-aminobutyric acid, citrulline homocysteine, homoserine, ornithine and methionine sulfone.
Additional types of prodrugs are also encompassed by the invention. For instance, free carboxyl groups can be derivatized as amides or alkyl esters. The amide and ester moieties can incorporate groups including, but not limited to, ether, amine, and carboxylic acid functionalities. Free hydroxy groups can be derivatized using groups including, but not limited to, hemisuccinates, phosphate esters, dimethylaminoacetates, and phosphoryloxymethyloxycarbonyls, as outlined in D. Fleisher, R. Bong, B. H. Stewart, Advanced Drug Delivery Reviews 19:115 (1996). Carbamate prodrugs of hydroxy and amino groups are also encompassed by the invention, as are carbonate prodrugs and sulfate esters of hydroxy groups. Derivatization of hydroxy groups as (acyloxy)methyl and (acyloxy)ethyl ethers wherein the acyl group may be an alkyl ester, optionally substituted with groups including but not limited to ether, amine and carboxylic acid functionalities, or where the acyl group is an amino acid ester as described above, are also encompassed by the invention. Prodrugs of this type are described in R. P. Robinson et al., J. Medicinal Chemistry 39:10 (1996).
This invention is directed to novel macrolide compounds, to methods of making them, and to pharmaceutical compositions comprising them. The invention is further directed to methods of treating or preventing bacterial and protozoal infections in mammals (e.g., humans), fish, and birds, as well as to methods of treating or preventing other diseases and conditions such as, but not limited to, cancer, atherosclerosis, and gastric motility disorders.
Specific compounds of the invention are of Formula 2, and are listed in Table 1:
The mass spectra (MS) and yield information provided in Table 1 are with regard to the preparation of compounds 2(a)-2(n) as described below in the Examples. Compounds of Formula 2 can be prepared according to the method shown in Scheme 1: 
According to Scheme 1, compounds of Formula 2 can be prepared from compounds of Formula e, the synthesis of which is disclosed by U.S. Pat. Nos. 4,474,768 and 4,517,359, both of which are incorporated herein by reference. According to this method, a carbonate compound of Formula f is prepared from compound e using synthetic conditions known to those skilled in the art. Preferred conditions comprise the use of ethylene carbonate and a base such as potassium carbonate in a solvent such as ethyl acetate. The carbonate f can then be reacted with a Grignard reagent to provide compound 2.
Other compounds of the invention are those of Formula 3, specific examples of which are listed in Table 2:
As above, the MS and yield information provided in Table 2 are with regard to the preparation of compounds 3(a)-3(m) as described below in the Examples. Compounds of Formula 3 can be prepared according to the method shown in Scheme 2: 
According to Scheme 2, compounds of Formula 3 can be readily prepared from compounds of Formula g, which can be prepared according to Scheme 1. In particular, compounds of Formula 3 can be prepared by dissolving compounds of Formula a in a liquid amine and subsequently stirring the resulting mixture for a sufficient time and at a sufficient temperature (e.g., about 2 days at room temperature). Alternatively, compounds of Formula g and a liquid or solid amine can be dissolved in a solvent, which can then be stirred for a sufficient time and at a sufficient temperature to yield compounds of Formula 3.
Still other compounds of the invention are those of Formula 4, specific examples of which are listed in Table 3:
Wherein the MS and yield information provided in Table 3 are with regard to the preparation of compounds 4(a)-4(b) as described below in the Examples. Compounds of Formula 4 can be prepared according to the method shown in Scheme 3: 
According to Scheme 3, compounds of Formula 4 can be readily prepared from compounds of Formula h, which in turn can be prepared according to the method of Scheme 1. In particular, compounds of Formula 4 can be prepared by reacting compounds of Formula h with an amine oxidizing reagent in a suitable solvent such as, but not limited to, ethyl acetate and tetrahydrofuran (THF). Suitable amine oxidizing agents include, but are not limited to, N-bromosuccinimide (NBS), N-chlorosuccinimide (NCS), iodine, and bromine.
Other examples of compounds of the invention and preferred methods of their synthesis are provided in the Examples below.
Compounds of the present invention can have asymmetric carbon atoms, and diastereomeric mixtures of them can be separated into their individual diastereomers on the basis of their physical chemical differences by methods known to those skilled in the art, for example, by chromatography or fractional crystallization. Enantiomers can be separated by converting the enantiomeric mixtures into a diastereomeric mixture by reaction with an appropriate optically active compound (e.g., alcohol), separating the diastereomers and converting (e.g., hydrolyzing) the individual diastereomers to the corresponding pure enantiomers. All such isomers, including diastereomer mixtures and pure enantiomers are considered as part of the invention.
Compounds of the invention (i.e., compounds of Formula 1) that are basic in nature are capable of forming a wide variety of different salts with various inorganic and organic acids. Although such salts must be pharmaceutically acceptable for administration to animals, it is often desirable in practice to initially isolate the compound of the invention from the reaction mixture as a pharmaceutically unacceptable salt and then simply convert the latter back to the free base compound by treatment with an alkaline reagent and subsequently convert the latter free base to a pharmaceutically acceptable acid addition salt. The acid addition salts of the base compounds of this invention are readily prepared by treating the base compound with a substantially equivalent amount of the chosen mineral or organic acid in an aqueous solvent medium or in a suitable organic solvent, such as methanol or ethanol. Upon careful evaporation of the solvent, the desired solid salt is readily obtained. The desired acid salt can also be precipitated from a solution of the free base in an organic solvent by adding to the solution an appropriate mineral or organic acid.
Compounds of the invention that are acidic in nature are capable of forming base salts with various pharmacologically acceptable cations. Examples of such salts include the alkali metal or alkaline-earth metal salts and particularly, the sodium and potassium salts. These salts may be prepared by conventional techniques. The chemical bases which are used as reagents to prepare the pharmaceutically acceptable base salts of this invention are those which form non-toxic base salts with the acidic compounds of the invention. Non-toxic base salts include those derived from such pharmacologically acceptable cations such as, but not limited to, sodium, potassium calcium, and magnesium. These salts can be prepared by treating the corresponding acidic compounds with an aqueous solution containing the desired pharmacologically acceptable cations and then evaporating the resulting solution to dryness, preferably under reduced pressure. Alternatively, they may be prepared by mixing lower alkanolic solutions of the acidic compounds and the desired alkali metal alkoxide together, and then evaporating the resulting solution to dryness in the same manner as before. In either case, stoichiometric quantities of reagents are preferably employed in order to ensure completeness of reaction and maximum yields of the desired final product.
The activity of the compounds of the present invention against bacterial and protozoa pathogens is demonstrated by the compound""s ability to inhibit growth of defined strains of human (Assay I) or animal (Assays II and III) pathogens.
Assay I, described below, employs conventional methodology and interpretation criteria and is designed to provide direction for chemical modifications that may lead to compounds that circumvent defined mechanisms of macrolide resistance. In Assay I, a panel of bacterial strains is assembled to include a variety of target pathogenic species, including representatives of macrolide resistance mechanisms that have been characterized. Use of this panel enables the chemical structure/activity relationship to be determined with respect to potency, spectrum of activity, and structural elements or modifications that may be necessary to obviate resistance mechanisms. Bacterial pathogens that comprise the screening panel are shown below in Table 4. In many cases, both the macrolide-susceptible parent strain and the macrolide-resistant strain derived from it are available to provide a more accurate assessment of the compound""s ability to circumvent the resistance mechanism. Strains that contain the gene with the designation of ermA/ermB/ermC are resistant to macrolides, lincosamides, and streptogramin B antibiotics due to modifications (methylation) of 23S rRNA molecules by an Erm methylase that generally prevent the binding of all three structural classes. Two types of macrolide efflux have been described; msrA encodes a component of an efflux system in staphylococci that prevents the entry of macrolides and streptogramins while mefA/E encodes a transmembrane protein that appears to efflux only macrolides. Inactivation of macrolide antibiotics can occur and can be mediated by either a phosphorylation of the 2xe2x80x2-hydroxyl (mph) or by cleavage of the macrocyclic lactone (esterase). The strains can be characterized using conventional polymerase chain reaction (PCR) technology and/or by sequencing the resistance determinant. The use of PCR technology in this application is described in J. Sutcliffe et al., xe2x80x9cDetection Of Erythromycin-Resistant Determinants By PCRxe2x80x9d, Antimicrobial Agents and Chemotherapy, 40(11):2562-2566 (1996). The antibacterial assay is performed in microtiter trays and interpreted according to Performance Standards for Antimicrobial Disk Susceptibility Testsxe2x80x94Sixth Edition; Approved Standard, published by The National Committee for Clinical Laboratory Standards (NCCLS) guidelines; the minimum inhibitory concentration (MIC) is used to compare strains. acr AB or acr AB-like indicates that an intrinsic multidrug efflux pump exists in the strain. Compounds are initially dissolved in dimethylsulfoxide (DMSO) as 40 mg/mL stock solutions.
Assay II, as described below, is utilized to test for activity against Pasteurella multocida and Assay III is utilized to test for activity against Pasteurella haemolytica. 
This assay is based on the liquid dilution method in microliter format. A single colony of P. multocida (strain 59A067) is inoculated into 5 mL of brain heart infusion (BHI) broth. The test compounds are prepared by solubilizing 1 mg of the compound in 125 mL of dimethylsulfoxide (DMSO). Dilutions of the test compound are prepared using uninoculated BHI broth. The concentrations of the test compound used range from 200 mg/mL to 0.098 mg/mL by two-fold serial dilutions. The P. multocida inoculated BHI is diluted with uninoculated BHI broth to make a 104 cell suspension per 200 ml. The BHI cell suspensions are mixed with respective serial dilutions of the test compound, and incubated at 37xc2x0 C. for 18 hours. The minimum inhibitory concentration (MIC) is equal to the concentration of the compound exhibiting 100% inhibition of growth of P. multocida as determined by comparison with an uninoculated control.
This assay is based on the agar dilution method using a Steers Replicator. Two to five colonies isolated from an agar plate are inoculated into BHI broth and incubated overnight at 37xc2x0 C. with shaking (200 rpm). The next morning, 300 mL of the fully grown P. haemolytica preculture is inoculated into 3 mL of fresh BHI broth and is incubated at 37xc2x0 C. with shaking (200 rpm). The appropriate amounts of the test compounds are dissolved in ethanol and a series of two-fold serial dilutions are prepared. Two mL of the respective serial dilution is mixed with 18 mL of molten BHI agar and solidified. When the inoculated P. haemolytica culture reaches 0.5 McFarland standard density, about 5 mL of the P. haemolytica culture is inoculated onto BHI agar plates containing the various concentrations of the test compound using a Steers Replicator and incubated for 18 hours at 37xc2x0 C. Initial concentrations of the test compound range from about 100 to about 200 mg/mL. The MIC is equal to the concentration of the test compound exhibiting 100% inhibition of growth of P. haemolytica as determined by comparison with an uninoculated control.
The in vivo activity of the compounds of the invention can be determined by conventional animal protection studies well known to those skilled in the art, usually carried out in mice.
Mice are allotted to cages (10 per cage) upon their arrival, and allowed to acclimate for a minimum of 48 hours before being used. Animals are inoculated with 0.5 mL of a 3xc3x97103 CFU/mL bacterial suspension (P. multocida strain 59A006) intraperitoneally. Each experiment has at least 3 non-medicated control groups including one infected with 0.1xc3x97 challenge dose and two infected with 1xc3x97 challenge dose; a 10xc3x97 challenge data group may also be used. Generally, all mice in a given study can be challenged within about 30 to about 90 minutes, especially if a repeating syringe (such as a Cornwallxc3xa2 syringe) is used to administer the challenge. Thirty minutes after challenging has begun, the first compound treatment is given. It may be necessary for a second person to begin compound dosing if all of the animals have not been challenged at the end of 30 minutes. The routes of administration are subcutaneous or oral doses. Subcutaneous doses are administered into the loose skin in the back of the neck whereas oral doses are given by means of a feeding needle. In both cases, a volume of 0.2 mL is used per mouse. Compounds are administered 30 minutes, 4 hours, and 24 hours after challenge. A control compound of known efficacy administered by the same route is included in each test. Animals are observed daily, and the number of survivors in each group is recorded. The P. multocida model monitoring continues for 96 hours (four days) post challenge.
The PD50 is a calculated dose at which the compound tested protects 50% of a group of mice from mortality due to the bacterial infection which would be lethal in the absence of drug treatment.
The compounds of the invention and their pharmaceutically acceptable salts, solvates and prodrugs (herein also referred to as xe2x80x9cactive compounds of this inventionxe2x80x9d) can be administered alone or in combination with pharmaceutically acceptable carriers, in either single or multiple doses. Suitable pharmaceutical carriers include inert solid diluents or fillers, sterile aqueous solutions and various organic solvents. The pharmaceutical compositions formed by combining the active compounds of this invention can then be readily administered in a variety of dosage forms such as, but not limited to, tablets, powders, lozenges, syrups, and injectable solutions. These pharmaceutical compositions can, if desired, contain additional ingredients such as, but not limited to, flavorings, binders, and excipients. Thus, for purposes of oral administration, tablets containing various excipients such as sodium citrate, calcium carbonate, and calcium phosphate may be employed along with various disintegrants such as starch, methylcellulose, alginic acid, and certain complex silicates, together with binding agents such as polyvinylpyrrolidone, sucrose, gelatin, and acacia. Additionally, lubricating agents such as magnesium stearate, sodium lauryl sulfate and talc are often useful for tableting purposes. Solid compositions of a similar type can also be employed as fillers in soft and hard filled gelatin capsules. Preferred materials for this include lactose or milk sugar and high molecular weight polyethylene glycols. When aqueous suspensions or elixirs are desired for oral administration, the essential active ingredient therein can be combined with various sweetening or flavoring agents, coloring matter or dyes and, if desired, emulsifying or suspending agents, together with diluents such as water, ethanol, propylene glycol, glycerin, and combinations thereof.
For parenteral administration, solutions containing an active compound of this invention or a pharmaceutically acceptable salt thereof in sesame or peanut oil, aqueous propylene glycol, or in sterile aqueous solution can be employed. Such aqueous solutions should be suitably buffered if necessary and the liquid diluent first rendered isotonic with sufficient saline or glucose. These particular aqueous solutions are especially suitable for intravenous, intramuscular, subcutaneous, and intraperitoneal administration. The sterile aqueous media employed are all readily available by standard techniques known to those skilled in the art.
To implement the methods of this invention, an effective dose of an active compound of this invention is administered to a susceptible or infected animal (including mammals, fish and birds) by parenteral (i.v., i.m. or s.c.), oral, or rectal routes, or locally as a topical application to the skin and/or mucous membranes. The route of administration will depend on the mammal, fish or bird that is being treated. The effective dose will vary with the severity of the disease, and the age, weight and condition of the animal. However, the daily dose will usually range from about 0.25 to about 150 mg/kg body weight of the patient to be treated, preferably from about 0.25 to about 25 mg/kg.